The present invention relates to a conveyor chain for three-dimensional conveyor line, in which a plurality of chain links each having a top plate provided on a link body thereof is connected endlessly to each other by shaft pins to three-dimensionally convey such appropriate products as beverages, foods, pharmaceuticals, and other similar products while supporting them stably on the top plates.
Heretofore, there have been provided various types of conveyor chains in which each chain link has a top plate provided thereon. The conventional conveyor chain links include, for example, a slat type conveyor chain apparatus used in a conveyor disclosed in the Japanese Published Unexampled Utility Model Application No. 145217 of 1990. The conveyor chain link known from the disclosure has a slat provided thereon, and a plurality of the chain links is made up into the conveyor. The slat has a plurality of projections formed at the front end thereof, and as many cuts formed at the rear end thereof as the projections. The cuts are formed in positions corresponding to the projections and larger than the projections. In the conveyor, the chain links are connected endlessly to each other with the rear end of a preceding one of two successive chain links being coupled to the front end of the following one with a constant gap between the cut of the preceding slat and projection of the following slat. Each of the chain links thus connected together is pivotable vertically and horizontally in relation to preceding and following ones.
Also, there has been provided a conveyor line chain in which a plurality of chain links each having a generally crescent top plate provided thereon is successively connected to each other.
In the above-mentioned slat type convey chain apparatus used in the conveyor, however, when the conveyor travels in a curved direction, the gap between the adjacent slats (top plates) is increased outside the center line of the curved track and a part of a product being conveyed is likely to fall into the increased gap. For this reason, the wider the slat (top plate), the more difficult it is to stably carry the product.
Also, when the conveyor line made up of the chain links each with the generally crescent top plate travels in a curved direction, the interval between the adjacent top plates will not be increased outside the center line of the curved track; however, when the conveyance shifts from horizontal to oblique (inclined or declined) or from oblique to horizontal, the lateral edges of the adjacent top plates are moved vertically more than the central portions and the product carried on the conveying surface (top plates) is thrust up as the case may be. Therefore, the conveyor made up of such chain links cannot be relied upon for stable conveyance of products.
Further, in the conveyor chain made up of the chain links each having the generally crescent top plate, when each of the chain links is strongly pulled forward while the tension of the entire chain is high for example, the front and rear edges of the top plate are likely to be lifted up slightly and also engagement of each of the chain links on a sprocket which drives the chain causes a noise.
The present invention has an object to overcome the above-mentioned drawbacks of the conventional art by providing a conveyor chain for three-dimensional conveyor line, which has a relatively wide conveying surface and can convey products without thrust-up, stalling or overturn of any of them during oblique conveyance or when each chain link engages on a sprocket.
The present invention has another object to provide a conveyor chain for three-dimensional conveyor line, in which the gap between two adjacent top plates is constant and small during conveyance in a linear or curved direction and which can make three-dimensional conveyance of products stably and smoothly.
The present invention has still another object to provide a conveyor chain for three-dimensional conveyor line, which is relatively simple in construction, easy to produce, and suitable for mass production, and can be produced and operated at low costs.
The above object can be attained by providing a conveyor chain for three-dimensional conveyor line, in which a plurality of chain links S each with a top plate provided on a link body thereof is connected endlessly to each other by shaft pins D for three-dimensional conveyance of products, wherein:
the link body includes a projecting head portion 1 projecting forward and having a bearing space 5 defined by a curved inner wall, and a pair of leg portions 2 projecting reward;
the leg portions 2 in pair of one chain link have the shaft pin D penetrated and fixed across them and the projecting head portion 1 of a next chain link S is disposed between the pair of leg portions 2;
the projecting head portion 1 is shaped to freely be pivoted vertically about, and longitudinally of, the shaft pin D;
the top plate includes a front plate portion B1 and rear plate portion A2, each portions formed defining their boundary a semicircular line whose center is laid nearly at the center of the projecting head portion 1 in such a manner that the front plate portion B1 has a generally semicircular shape while the rear plate portion A2 is concave at the front end thereof correspondingly to the semicircular shape of the front plate portion B1;
the rear plate portion A2 is integral with the rear upper portion of the link body while the front plate portion B1 has on the lower front side thereof a bearing block projecting downward and which is received in the bearing space 5 of the projecting head portion 1; and
the bearing block has the shaft pin D penetrated through it so that the bearing block is prevented from being disengaged from the bearing space 5 and the rear plate portion A2 can be pivoted laterally of the front plate portion B1.
the rear plate portion A2 is integral with the rear upper portion of the link body while the front plate portion B1 has on the lower front side thereof a bearing block projecting downward and which is received in the bearing space 5 of the projecting head portion 1; and
the bearing block has the shaft pin D penetrated through it so that the bearing block is prevented from being disengaged from the bearing space 5 and the rear plate portion A2 can be pivoted laterally of the front plate portion B1.
When the conveyor chain constructed as above travels horizontally in a curved direction, the rear plate portion A2 of one chain link S is pivoted laterally of the front plate portion B1 with no gap (or a gap which is constant and extremely small, if any) between the front edge of the rear plate portion A2 and the rear edge of the front plate B1, so that the product can be conveyed more stably.
Especially, even in case the top plate is shaped to greatly overhang laterally of the link body, since there takes place no gap (a gap which is constant and extremely small) between the front edge of the rear plate portion A2 and the rear edge of the front plate portion B1 when the chain travels horizontally in a curved direction, the front and rear plate portions B1 and A2 provide a rather wide conveying surface which permits to convey the product more stably.
In addition, in case the chain travels obliquely (inclined or declined), the rear edge of the rear plate portion A2 of the preceding one of two adjacent chain link S is turned an appropriate angle in relation to the front edge of the front plate portion B1 of the following chain link S, and the front plate portion B1 and rear plate portion A2 of the same chain link S tilt together without thrust-up, stalling or overturning of the bottom of the product on the plate portions B1 and A2. Further, since the chain link S is relatively simple in construction, so the chain according to the present invention is relatively simple in construction, easy to produced, and suitable for mass production, and can be produced and operated at low costs.
As set forth in claim 2, it is desirable that each of the chain link S should have projections 10 formed at the front edge of the front plate portion B1 and recesses 7 formed in the rear edge of the rear plate portion A2 correspondingly to the projections 10 to receive the projections 10, respectively.
Because of the above construction of the chain link S, the square shaped wave gap between the rear plate portion A2 of the forward one of two adjacent chain links S and the front plate portion B1 of the rearward adjacent chain link S shall be defined straightly and continuously, so that the product being conveyed is not easily be stalled or overturned. Thus, the conveyor chain can convey the products more stably.
Also, as set forth in claim 3, it is desirable that the bearing block formed on the lower side of the front plate portion B1 should be divided into two parts, front and rear, the rear bearing block B2 be formed integrally with the front plate portion B1 while the front bearing block C should be formed separately from the front plate portion B1 and front bearing block B2.
Because of the above bearing block construction, the front bearing block C may be formed from various materials and any one of the bearing blocks C thus made is selected for an intended use. For example, during operation of the conveyor chain, the front bearing block C is applied with a considerably large load from the surrounding front inner wall surface of the bearing space 5 of the projecting head portion 1 and the shaft pin D and also in sliding contact with the front inner wall surface of the bearing space 5 and thus it is easily abraded. So, it should preferably be formed from a highly durable, strong or abrasion-resistant material, so that the entire chain link S can be highly durable, strong or abrasion-resistant.
The highly durable, strong or abrasion-resistant material is relatively expensive, but since it suffices to from only the front bearing block C from such a material, the production cost for the entire chain can be reduced and chain links S having the front bearing blocks formed from various materials can freely be combined to build widely applicable conveyor chains.
Particularly, since the bearing block consists of the rear and front bearing blocks B2 and C, the force of the front bearing block C will not have any influence on the rear bearing block B2 and front plate portion B1 while the force from the shaft pin D is transmitted to the front bearing block C even in case the entire chain is under a high tension and the chain links S are pulled strongly frontward. Thus the front and rear edges of the front plate portion B1 will not be lifted up.
Since the rear bearing block B2 is formed integrally with the front plate portion B1, the latter may be formed from a material which is not so durable or strong. For example, in case the top plate B itself is formed from rubber or the like, the product being conveyed can stably be carried on the front plate portion B1 without slipping thereon.
Further, as set forth in claim 4, the front bearing block C should desirably be formed from a low-abrasion or high oil-content material, so that it can smoothly move in the bearing space 5 and in relation to the shaft pin D and thus it has a higher durability. The entire chain link S will have a longer service life and the conveyor chain made up of such chain links S can be maintained more easily.
Furthermore, as set forth in claim 5, the front plate portion B1 and rear bearing block B2 should desirably be formed from a high coil-content material or an appropriately elastic material, so that a sprocket driving the chain and the rear bearing block B2 can be put in smooth contact with each other without occurrence of any noise when the rear bearing block B2 is put into contact with the sprocket which drives the chain.